a birthday toast -- to stephen sondheim, the legendary composer who revolutionized broadway. host david hyde pierce and an all-star cast of broadway's best -- patti lupone, audra mcdonald, mandy patinkin, bernadette peters, elaine stritch -- and many more -- join the new york philharmonic and conductor paul gemignani for an extra-special birthday tribute. it's "sondheim: the birthday concert," next on "great performances." ♪